DZone, Inc. | www.dzone.com

By Ben Ellingson and Matthew McCullough

An IntroductIon to the LAnguAge And tooLs

ob

ject

ive

-c f

or

the

iPh

on

e a

nd

iPad

w

ww

.dzo

ne.

com

Ge

t M

ore

Re

fcar

dz!

Vis

it r

efca

rdz.

com

#110

contents IncLude:n An Introduction to the Language and Toolsn The Syntaxn Memory Managementn Toolsn Debuggingn XCode Keyboard Shortcuts and more...

Hot Tip

The keyword @interface can distract developers coming from some languages such as Java, suggesting this is a mere contract. However, @interface is indeed the keyword for defining the properties and method signatures of a concrete class in Obj-C.

Objective-C is the primary language used to create applications for Apple’s Mac OS X and iOS (iPhone and iPad) platforms. Objective-C was created by Brad Cox and Tom Love in the early 1980s. In 1988, Objective-C was licensed by NeXT, a company founded and helmed by Steve Jobs during his absence from Apple. Apple acquired NeXT in 1996, bringing Objective-C to the Macintosh platform.

Objective-C is an object oriented superset of ANSI C. Its object syntax is derived from Smalltalk. It supports single inheritance, implementation of multiple interfaces via the @protocol syntax, and the redefinition and augmentation of (open) classes via categories. Apple’s iPhone SDK for the iOS mobile operating system offers developers a rich set of Objective-C APIs. This free SDK, which includes the Xcode IDE, is used to create applications for the iPhone, iPad, and iPod Touch.

Get over 90 DZone Refcardz FREE from Refcardz.com!

Objective-Cfor the iPhone and iPad

the syntAx

Class DeclarationObjective-C classes typically include an interface .h and an implementation .m pair of files. The .h file contains property and method declarations. The .m file contains method implementations.

Example .h interface file#import <Foundation/Foundation.h>@interface Speaker : NSObject { NSInteger *ID; NSString *name; }@property NSInteger *ID;@property(nonatomic,retain) NSString *name;- (void) doSomething: (NSString *) value anotherValue: (int) value2;@end

Example .m implementation file#import “Speaker.h”@implementation Speaker@synthesize ID,name;- (void) doSomething: (NSString *) value anotherValue: (int) value2 { // do something}@end

InheritanceClass inheritance is specified in the .h interface file with the syntax: @interface <MyClass> : <ParentClass>. The following example tells the compiler that the Employee class inherits from (extends) the Person class.

// Employee.h file@interface Employee : Person {}@end

InterfacesObjective-C interfaces are created using the @protocol declaration. Any class can implement multiple interfaces. Interfaces are typically declared in a .h header file and can be included via #import statements in the .h header file of other classes.

// Mappable.h: Declare the Mappable @protocol@protocol Mappable- (double) latitude;- (double) longitude;@end

// Location.h: Specify that Location class implements the Mappable // @protocol#import “Mappable.h”@interface Location : NSObject <Mappable> {}@end

// Location.m: Provide implementations for the Mappable methods@implementation Location- (double) latitude { return 46.553666;}- (double) longitude { return -87.40551;}@end

Primitive Data TypesAs a superset of ANSI C, Objective-C supports its same primitive data types.

int Integral numbers without decimal points

float Numbers with decimal points

DZone, Inc. | www.dzone.com

2objective-c for the iPhone and iPad

- (void) setPages: (int) p;

Method type (class or instance)

return type

method name

parameter type

parameter name

[book setPages: 100];

method target

method name

parameter value

double Same as float with twice the accuracy or size

char Store a single character such as the letter ‘a’

BOOL Boolean values with the constants YES or NO

Common Object Data TypesNSObject Root class of the object hierarchy

NSString String value

NSArray Collection of elements, fixed size, may include duplicates

NSMutableArray Variable sized array

NSDictionary Key-value pair collection

NSMutableDictionary Variable sized key-value pair collection

NSSet Unordered collection of distinct elements

NSData Byte buffer

NSURL URL resource

Instance VariablesClass instance variables are declared within a curly braced {} section of the .h file.

// Book.h: Variables declared in a header file@interface Book : NSObject { NSString *title; NSString *author; int pages;}@end

Notice that the object variable declarations are preceded by * symbol. This indicates that the reference is a pointer to an object and is required for all object variable declarations.

Dynamic TypingObjective-C supports dynamic typing via the id keyword.

NSString *name1 = @”Bob”;// name2 is a dynamically typed NSString objectid name2 = @”Bob”;if ([name1 isEqualToString:name2]) { // do something}

MethodsMethods are declared in the .h header file and implemented in the .m implementation file.

// Book.h: Declare methods in the header file@interface Book : NSObject {}- (void) setPages: (int) p;- (int) pages;@end

// Book.m: Implement methods in the implementation file@implementation Book- (void) setPages: (int) p { pages = p;}- (int) pages { return pages;}@end

Method Declaration Syntax

Method Invocation SyntaxMethod invocations are written using square bracket [] notation.

Using Dot Notation Method InvocationObjective-C 2.0 added the ability to invoke property accessor methods (getters/setters) using “.” notation.

// Using dot notation calls the book instance’s setAuthor methodbook.author = @”Herman Melville”;// equivalent to[book setAuthor: @”Herman Melville”];

Multi Parameter MethodsMulti-Parameter methods are more verbose than other languages. Each parameter includes both an external name, data type, and a local variable name. The external parameter name becomes a formal part of the method name.

// declare a method with multiple parameters- (void) addBookWithTitle: (NSString *) aTitle andAuthor: (NSString *) anAuthor;

// invoke a method with multiple parameters[self addBookWithTitle: @”Moby Dick” andAuthor: @”Herman Melville”];

Self and Super PropertiesObjective-C objects include a self property and a super property. These properties are mutable and can be assigned in an advanced technique called “swizzling”. Most commonly, the self attribute is used to execute a method on the enclosing object.

[self setAuthor: @”Herman Melville”];

// Invoke methods on the “super” property to execute parent class // behavior. a method that overrides a parent class method will likely call // the parent class method- (void) doSomething: (NSString *)value { [super doSomething: value]; // do something derived-class specific}

Properties using @property and @synthesizeObjective-C 2.0 added property declaration syntax in order to reduce verbose coding of getter and setter methods.

// use of @property declaration for the title variable is equivalent to // declaring a “setTitle” mutator and “title” accessor method.@interface Book : NSObject { NSString *title;}@property (retain, nonatomic) NSString *title;@end

// use the @synthesize declaration in the .m implementation file// to automatically implement setter and getter methods. @implementation Book@synthesize title, author; //Multiple variables@synthesize pages; //Single variable@end

Multiple variables may be included in a single @synthesize declaration. Alternatively, a class may include multiple @synthesize declarations.

@property AttributesProperty attributes specify behaviors of generated getter and setter methods. Attribute declarations are placed in parenthesis () after the @property declaration. The most common values used are (retain, nonatomic). retain indicates that the [retain] method should be called on the newly assigned value object. See the memory management section for further explanation. nonatomic indicates that the assignment operation does not check for thread access protection, which may be necessary in multi-threaded environments. readonly may be specified to indicate the property’s value can not be set.

Object InitializationObject instances are created in two steps. First, with a call to alloc and second, with a call to init.

DZone, Inc. | www.dzone.com

3objective-c for the iPhone and iPad

// example of 2 step object initializationBook *book = [[Book alloc] init];// equivalent to Book *book2 = [Book alloc];book2 = [book init];

In order to perform specific object initialization steps, you will often implement the init or an initWith method. Notice the syntax used around the self property in the following example. This is a standard init pattern found in Objective-C. Also notice the method uses a dynamic id return type.

// Event.m: Implementation overrides the “init” method to assign a default // date value@implementation Event- (id) init { self = [super init]; if (self != nil) { self.date = [[NSDate alloc] init]; } return self;}@end

Class ConstructorsClasses often include constructor methods as a convenience. The method type is + to indicate that it is a class (static) method.

// Constructor method declaration+ (Book *) createBook: (NSString *) aTitle withAuthor: (NSString *) anAuthor;

// Invoke a class constructorBook *book2 = [Book createBook: @”Moby Dick” withAuthor: @”Herman Melville”];

#import Statements#import statements are required to declare the classes and frameworks used by your class. #import statements can be included at the top of both .h header and .m implementation files.

// import a class#import “Book.h”

// import a framework#import <MapKit/MapKit.h>

Control Flow// basic for loopfor (int x=0; x < 10; x++) { NSLog(@”x is: %d”,x);}

// for-in loop NSArray *values = [NSArray arrayWithObjects:@”One”,@”Two”,@”Three”,nil];

for(NSString *value in values) { // do something}

// while loop BOOL condition = YES; while (condition == YES) { // doSomething }

// if / else statements BOOL condition1 = NO;BOOL condition2 = NO;if (condition1) { // do something } else if(condition2) { // do other thing} else { // do something else}

// switch statementint x = 1;switch (x) { case 1: // do something break; case 2: // do other thing break; default: break;}

StringsObjective-C string literals are prefixed with an “@” symbol (e.g. @”Hello World”). This creates instances of the NSString class; instead of C language CFStrings.

// create a string literal via the “@” symbolNSString *value = @”foo bar”;NSString *value2 = [NSString stringWithFormat:@”foo %@”,@”bar”];// string comparisonif ([value isEqualToString:value2]) { // do something}NSURL *url = [NSURL URLWithString:@”http://www.google.com”];NSString *value3 = [NSString stringWithContentsOfURL:url];NSString *value4 = [NSString stringWithContentsOfFile: @”file.txt”];

NSLog / NSString FormattersFormatters are character sequences used for variable substitution in strings.

%@ for objects%d for integers%f for floats// Logs “Bob is 10 years old”NSLog(@”%@ is %d years old”, @”Bob”, 10);

Data StructuresUsing NSArray// Create a fixed size array. Notice that nil termination is requiredNSArray *values = [NSArray arrayWithObjects:@”One”,@”Two”,nil];// Get the array sizeint count = [values count];// Access a valueNSString *value = [values objectAtIndex:0];// Create a variable sized arrayNSMutableArray *values2 = [[NSMutableArray alloc] init];[values2 addObject:@”One”];

Using NSDictionaryNSDictionary *di = [NSDictionary dictionaryWithObjectsAndKeys: @”One”,[NSNumber numberWithInt:1], @”Two”,[NSNumber numberWithInt:2],nil];NSString *one = [di objectForKey: [NSNumber numberWithInt:1]];NSMutableDictionary *di2 = [[NSMutableDictionary alloc] init];[di2 setObject:@”One” forKey:[NSNumber numberWithInt:1]];

Memory ManagementObjective-C 2.0 includes garbage collection. However, garbage collection is not available for iOS apps. iOS apps must manage memory by following a set of object ownership rules. Each object has a retain count which indicates the number of objects with an ownership interest in that object. Ownership of an object is automatically taken when you call a method beginning with alloc, prefixed with new, or containing copy. Ownership is manually expressed by calling the retain method. You relinquish object ownership by calling release or autorelease.

When an object is created it has a retain count of 1When the “retain” message is sent to an object, the retain count is incremented by 1 When the “release” message is sent to an object, the retain count is decremented by 1When the retain count reaches 0, it is deallocated

// alloc sets the retain count to 1Book *book = [[Book alloc] init];// do something...

// Release message decrements the retain count,// Retain count reaches 0. Book will be deallocated[book release];

dealloc MethodWhen an object’s retain count reaches 0, it is sent a dealloc message. You will provide implementations of the dealloc method, which will call release on the instances retained variables. Do not call dealloc directly.

// Book.m: Implement release of member variables- (void) dealloc{ [title release]; [author release]; [super dealloc];}

Autorelease PoolsAn autorelease pool (NSAutoreleasePool) contains references to

DZone, Inc. | www.dzone.com

4objective-c for the iPhone and iPad

objects that have received an autorelease message. When the autorelease pool is deallocated, it sends a release message to all objects in the pool. Using an autorelease pool may simplify memory management; however, it is less fine grained and may allow an application to hold onto more memory than it really needs. Be watchful of which types and size of objects you use with autorelease.

// call autorelease on allocated instance to add it to the autorelease poolBook *book = [[[Book alloc] init] autorelease];

CategoriesCategories are a powerful language feature which allows you to add methods to an existing class without subclassing. Categories are useful to extend the features of existing classes and to split the implementation of large classes into several files. Categories are not subclasses. Generally, do not use methods in a category to extend existing methods except when you wish to globally erase and redefine the original method. Categories can not add instance variables to a class.

// BookPlusPurchaseInfo.h adds purchase related methods to the Book class#import “Book.h”@interface Book (PurchaseInfo) - (NSArray *) findRetailers;@end// BookPlusPurchaseInfo.m implements the purchase related methods#import “BookPlusPurchaseInfo.h”@implementation Book (PurchaseInfo)- (NSArray *) findRetailers { return [NSArray arrayWithObjects:@”Book World”,nil];}@end

// call a method defined in the BookPlusPurchaseInfo categoryBook *book = [Book createBook:@”Moby Dick” withAuthor:@”Herman Melvile”];NSArray *retailers = [book findRetailers];

SelectorsSelectors create method identifiers using the SEL datatype. A value can be assigned to a SEL typed variable via the @selector() directive. Selectors, along with NSObject’s method performSelector: withObject: enable a class to choose the desired message to be invoked at runtime.

// Execute a method using a SEL selector and the performSelector methodid target = [[Book alloc] init]; // Action is a reference to the “doSomething” methodSEL action = @selector(doSomething); // The message sender need not know the type of target object // or the message that will be called via the “action” SEL[target performSelector: action withObject:nil ];

Working With FilesiOS applications have access to files in an app-specific home directory. This directory is a sand-boxed portion of the file system. An app can read and write files within this its own hierarchy, but it can not access any files outside of it.

// Get the path to a iOS App’s “Documents” directoryNSString *docDir = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];

// List the contents of a directoryNSFileManager *fileManager = [NSFileManager defaultManager];NSArray *files = [fileManager contentsOfDirectoryAtPath:docDir error:nil];for (NSString *file in files) { NSLog(file);}

// Create a directoryNSString *subDir = [NSString stringWithFormat:@”%@/MySubDir”,docDir];[fileManager createDirectoryAtPath:subDir attributes:nil];

// Does the file exist?NSString *filePath = [NSString stringWithFormat:@”%@/MyFile.txt”,docDir];BOOL exists = [fileManager fileExistsAtPath: filePath];

tooLs

XcodeThe IDE included in the iOS SDK is named Xcode. It is the

primary tool in the suite of utilities that ship with the SDK. Xcode has a long history but has been given a dramatic set of feature additions in the modern iPhone and iPad releases, including detection of common user-coded memory leaks and quick-fixing of other syntax and coding mistakes.

Plain text editors and command line Make files can be used to produce iOS applications. However, Xcode offers compelling features such as syntax highlighting and code completion. These features make writing Objective-C in the Xcode IDE a delight and a favorite of developers everywhere.

Once the code is in a valid-syntax state, compile it by choosing Build Build from the menus, or ⌘B. If there are code errors, they will appear as a yellow or red icon in the lower right corner of the IDE. Clicking on the icon will reveal a panel detailing the warnings and errors.

Deploying an application to the simulator has two simple steps. First, choose the Simulator target from the main Xcode toolbar. Building and Deploying can be done in one seamless step by pressing the Command and Enter keys. The simulator will receive the compiled application and launch it.

To deploy to an iPhone or iPad, first select Device from the aforementioned toolbar menu. Second, right click on the element beneath the Target node of the Groups and Files tree and choose Get Info. Choose the Properties tab and ensure the Identifier matches the name or pattern you established with Apple for your Provisioning Profile at http://developer.apple.com/iphone

DZone, Inc. | www.dzone.com

5objective-c for the iPhone and iPad

DebuggingThe Xcode platform provides a robust debugger and supplementary mechanisms for stepping through code. Breakpoints are easily set by single clicking in the gutter next to any line of code. A blue arrow indicates a breakpoint is set and active.

Once a breakpoint is hit, variables can be inspected and the stack examined via the key combination ⌘ + ⇧ + Y. The bottommost panel is called the console, and is where all logging output, written via calls such as NSLog(@“My counter is: %d”, myIntCount), is routed.

Hot Tip

During the debugging and testing phase of development, activate Zombies to place “markers” in deallocated memory, thereby providing a stack trace in the console if any invalid attempts are made to access the freed memory. This is accomplished in three simple steps: • Double-click the name of any node beneath the Executables group of an Xcode project. • In the dialog that opens, click the Arguments tab. • In the lower “Variables to be set” region, click the + button and create a new variable named “NSZombieEnabled” with its value set to “YES”.

Interface BuilderA tool as powerful as Xcode is Interface Builder. Its name clearly expresses its use for designing Objective-C NIBs and XIBs, which are the binary and XML form of user interface definition files on the Mac, iPhone, and iPad.

NIBs, though graphically designed, actually instantiate the objects declared via the tool when called upon via code. Accordingly, it may help to think of IB (as it is known in the

OrganizerThe Organizer window provides a list of favorite projects, enumerates your attached iOS devices, streams the current device console log to screen and displays details of past crash logs. It can be opened from Xcode via ⌘+^+O.

community) primarily as a class-instance designer and property value setter.

New elements can be added to a design canvas in a drag-and-drop WYSIWYG approach via the Library panel, which can be accessed via the ⌘ + ⇧ +L key combination. After saving changes, the design’s behavior can be immediately tested through the Simulate Interface command, which can be invoked via ⌘ + R.

SimulatorThe iPhone and iPad Simulator is another distinct application in the iPhone SDK that communicates and integrates with the Xcode IDE and with Interface Builder. In the Xcode section, we saw how to deploy our application to the Simulator, which both installs the application and launches it.

While the Simulator offers a great desktop testing experience that requires no purchase of hardware, it has a few shortcomings such as the lack of a camera, gyroscope, or GPS facilities. The lack of camera is somewhat mitigated by a supply of several stock photos in the Photo application. The harsh absence of a gyroscope is minimized only by the shake and rotate gestures possible through the Hardware menu. And last, the omission of a true GPS simulator is performed by GPS calls always resolving to 1 Infinite Loop, Cupertino, CA, USA.

The iPhone Simulator offers iPad, iPhone and iPhone 4 simulation modes. The modes are toggled via the Hardware Device menu.

The Simulator ships with a limited number of core applications; namely, the Photos, Settings, Camera, Contacts and Safari programs. These are the applications that offer API connectivity from the source code of your application. For a broader set of programs and more realistic mobile horsepower

By Paul M. Duvall

ABOUT CONTINUOUS INTEGRATION

Ge

t M

ore

Re

fcar

dz!

Vis

it r

efca

rdz.

com

#84

Continuous Integration:

Patterns and Anti-Patterns

CONTENTS INCLUDE:

■ About Continuous Integration

■ Build Software at Every Change

■ Patterns and Anti-patterns

■ Version Control

■ Build Management

■ Build Practices and more...

Continuous Integration (CI) is the process of building software

with every change committed to a project’s version control

repository.

CI can be explained via patterns (i.e., a solution to a problem

in a particular context) and anti-patterns (i.e., ineffective

approaches sometimes used to “fi x” the particular problem)

associated with the process. Anti-patterns are solutions that

appear to be benefi cial, but, in the end, they tend to produce

adverse effects. They are not necessarily bad practices, but can

produce unintended results when compared to implementing

the pattern.

Continuous Integration

While the conventional use of the term Continuous Integration

efers to the “build and test” cycle, this Refcard

expands on the notion of CI to include concepts such as

Aldon®

Change. Collaborate. Comply.

Pattern

Description

Private WorkspaceDevelop software in a Private Workspace to isolate changes

Repository

Commit all fi les to a version-control repository

Mainline

Develop on a mainline to minimize merging and to manage

active code lines

Codeline Policy

Developing software within a system that utilizes multiple

codelines

Task-Level CommitOrganize source code changes by task-oriented units of work

and submit changes as a Task Level Commit

Label Build

Label the build with unique name

Automated Build

Automate all activities to build software from source without

manual confi guration

Minimal DependenciesReduce pre-installed tool dependencies to the bare minimum

Binary Integrity

For each tagged deployment, use the same deployment

package (e.g. WAR or EAR) in each target environment

Dependency Management Centralize all dependent libraries

Template Verifi er

Create a single template fi le that all target environment

properties are based on

Staged Builds

Run remote builds into different target environments

Private Build

Perform a Private Build before committing changes to the

Repository

Integration Build

Perform an Integration Build periodically, continually, etc.

Send automated feedback from CI server to development team

ors as soon as they occur

Generate developer documentation with builds based on

brought to you by...

By Andy Harris

HTML BASICS

e.co

m

G

et

Mo

re R

efc

ard

z! V

isit

ref

card

z.co

m

#64

Core HTMLHTML and XHTML are the foundation of all web development.

HTML is used as the graphical user interface in client-side

programs written in JavaScript. Server-side languages like PHP

and Java also receive data from web pages and use HTML

as the output mechanism. The emerging Ajax technologies

likewise use HTML and XHTML as their visual engine. HTML

was once a very loosely-defi ned language with very little

standardization, but as it has become more important, the

need for standards has become more apparent. Regardless of

whether you choose to write HTML or XHTML, understanding

the current standards will help you provide a solid foundation

that will simplify all your other web coding. Fortunately HTML

and XHTML are actually simpler than they used to be, because

much of the functionality has moved to CSS.

common elementsEvery page (HTML or XHTML shares certain elements in

common.) All are essentially plain text

extension. HTML fi les should not be cr

processor

CONTENTS INCLUDE:■ HTML Basics■ HTML vs XHTML

■ Validation■ Useful Open Source Tools

■ Page Structure Elements■ Key Structural Elements and more...

The src attribute describes where the image fi le can be found,

and the alt attribute describes alternate text that is displayed if

the image is unavailable.Nested tagsTags can be (and frequently are) nested inside each other. Tags

cannot overlap, so <a><b></a></b> is not legal, but <a><b></

b></a> is fi ne.

HTML VS XHTMLHTML has been around for some time. While it has done its

job admirably, that job has expanded far more than anybody

expected. Early HTML had very limited layout support.

Browser manufacturers added many competing standar

web developers came up with clever workar

result is a lack of standarThe latest web standar

Browse our collection of 100 Free Cheat SheetsUpcoming RefcardzApache AntHadoopSpring SecuritySubversion

By Daniel Rubio

ABOUT CLOUD COMPUTING

Clo

ud

Co

mp

uti

ng

w

ww

.dzo

ne.

com

G

et

Mo

re R

efc

ard

z! V

isit

ref

card

z.co

m

#82

Getting Started with Cloud Computing

CONTENTS INCLUDE:■ About Cloud Computing■ Usage Scenarios■ Underlying Concepts ■ Cost■ Data Tier Technologies■ Platform Management and more...

Web applications have always been deployed on servers connected to what is now deemed the ‘cloud’.

However, the demands and technology used on such servers has changed substantially in recent years, especially with the entrance of service providers like Amazon, Google and Microsoft.

These companies have long deployed web applications that adapt and scale to large user bases, making them knowledgeable in many aspects related to cloud computing.

This Refcard will introduce to you to cloud computing, with an emphasis on these providers, so you can better understand what it is a cloud computing platform can offer your web applications.

USAGE SCENARIOS

Pay only what you consumeWeb application deployment until a few years ago was similar to most phone services: plans with alloted resources, with an incurred cost whether such resources were consumed or not.

Cloud computing as it’s known today has changed this. The various resources consumed by web applications (e.g. bandwidth, memory, CPU) are tallied on a per-unit basis (starting from zero) by all major cloud computing platforms.

also minimizes the need to make design changes to support one time events.

Automated growth & scalable technologiesHaving the capability to support one time events, cloud computing platforms also facilitate the gradual growth curves faced by web applications.

Large scale growth scenarios involving specialized equipment (e.g. load balancers and clusters) are all but abstracted away by relying on a cloud computing platform’s technology.

In addition, several cloud computing platforms support data tier technologies that exceed the precedent set by Relational Database Systems (RDBMS): Map Reduce, web service APIs, etc. Some platforms support large scale RDBMS deployments.

CLOUD COMPUTING PLATFORMS AND UNDERLYING CONCEPTS

Amazon EC2: Industry standard software and virtualizationAmazon’s cloud computing platform is heavily based on industry standard software and virtualization technology.

Virtualization allows a physical piece of hardware to be utilized by multiple operating systems. This allows resources (e.g. bandwidth, memory, CPU) to be allocated exclusively to individual operating system instances.

As a user of Amazon’s EC2 cloud computing platform, you are assigned an operating system in the same way as on all hosting

DZone, Inc.140 Preston Executive Dr.Suite 100Cary, NC 27513

888.678.0399919.678.0300

Refcardz Feedback Welcomerefcardz@dzone.com

Sponsorship Opportunities sales@dzone.com

Copyright © 2010 DZone, Inc. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by means electronic, mechanical, photocopying, or otherwise, without prior written permission of the publisher.

rev. 1.001 10/08/09

$7.9

5

DZone communities deliver over 6 million pages each month to

more than 3.3 million software developers, architects and decision

makers. DZone offers something for everyone, including news,

tutorials, cheatsheets, blogs, feature articles, source code and more.

“DZone is a developer’s dream,” says PC Magazine.

6objective-c for the iPhone and iPad

recoMMended BookABout the Authors

ISBN-13: 978-1-934238-75-2ISBN-10: 1-934238-75-9

9 781934 238752

50795

CPUs, testing on an actual iOS device is critical. Commercial apps that you’ve purchased from the iTunes App Store cannot be installed on the Simulator for DRM reasons and the vast difference in CPU architecture of x86 desktops and ARM mobile devices.

Xcode Keyboard ShortcutsCommon XCode Shortcuts⌘ = command ⎇ = alt ▲ = up ⇧ = shift ⏎ = return ^ = control

⎇ ⌘ ▲ toggle between .h and .m file

⌘ ⇧ d quickly open a file via search dialog

⌘ b build

⌘ ⏎ build and run

⌘ ⇧ k clean the build

⌘ ⇧ r go to console view

⌘ 0 go to project view

⌘ ⇧ e show / hide upper right pane

⎇ ⌘ ⇧ e show / hide all but the active document window

^ 1 while in file editor - show / navigate list of recent files

^ 2 while in file editor - show / navigate list of class methods

⌘ y build and debug

⎇ ⌘ p debugger continue

⎇ double-click open quick documentation for class at mouse cursor

Unit Testing and Code CoverageCurrently, the unit testing tools for Objective-C are less mature than those of other languages. XCode currently includes the OCUnit unit testing framework. OCUnit tests are coded similarly to those of xUnit tests in languages such as Java. The Google Toolbox for Mac provides several useful enhancements to OCUnit and is the testing solution currently recommended by ThoughtWorks for the iOS platform. Complementing OCUnit is OCMock, an Objective-C implementation of mock objects. CoverStory can be used in concert with OCUnit and OCMock to check the code coverage of your tests.

ResourcesSDKApple Developer Programs - http://developer.apple.com/

iOS SDK - http://developer.apple.com/iphone/index.action

TestingGoogle Toolbox for Mac - http://code.google.com/p/google-toolbox-for-mac/

OCMock - http://www.mulle-kybernetik.com/software/OCMock/

CoverStory - http://code.google.com/p/coverstory/

Blogs, Videos, BooksWWDC 2010 Session Videos - http://developer.apple.com/videos/wwdc/2010/

Objective-C Basics -http://en.wikibooks.org/wiki/Cocoa_Programming/Objective-C_basics

iPhone Development Wiki - http://iphonedevwiki.net/index.php/Main_Page

The Objective-C Programming Language -http://developer.apple.com/mac/library/documentation/Cocoa/Conceptual/ObjectiveC/

Bookmarks - http://delicious.com/matthew.mccullough/objectivec

Matthew McCullough is an energetic 15 year veteran of enterprise software development, open source education, and co-founder of Ambient Ideas, LLC, a Denver, Colorado, USA consultancy. Matthew is a published author, open source creator, speaker at over 100 conferences, and author of three of the top 10 Refcardz of all time. He writes frequently on software and presenting at his blog: http://ambientideas.com/blog.

Ben Ellingson is a software engineer and consultant. He is the creator of nofluffjuststuff.com, many related No Fluff Just Stuff websites and mobile applications. During Ben’s 13 years of development experience, he has helped create systems for conference management, video-on-demand, and online travel. You can keep up with Ben’s work at http://benellingson.blogspot.com and http://twitter.com/benellingson.

The second edition of this book thoroughly covers the latest version of the language, Objective-C 2.0. And it shows not only how to take advantage of the Foundation framework’s rich built-in library of classes but also how to use the iPhone SDK to develop programs designed for the iPhone/iPad platform.

Buy noWbooks.dzone.com/books/objective-c